1. Field of the Invention
The present invention relates to a contact terminal, and more particularly to a contact terminal for test socket in which the contact terminal is configured with upper and lower contact pins biased from each other with a coil spring arranged therebetween. The lower contact pin is featured with a pair of offset arms slidably moves along opposite surfaces of the upper contact pin.
2. Description of Related Art
A contact terminal for test socket disclosed in U.S. Pat. No. 7,025,602 issued to Hwang on Apr. 11, 2006 includes an upper and a lower contact pins having same structure and electrically connecting with each other, and a spring arranged between the upper and the lower contact pins and providing a repellent force for two contact pins to move away from each other along a vertical direction. The upper and lower contact pins both comprise a base portion, a pair of elastic arms extending downwardly from bottom sides of the base portion, two hooks with inclined guiding surfaces and respectively disposed at a free end of each elastic arm, and two openings defined on two opposite sides of the base portion. The upper and the lower contact pins are assembled together through the hooks of the upper contact pin matching with the openings of the lower contact pin and the hooks of the lower contact pin matching with the openings of the upper contact pin.
The contact terminal described above has following disadvantages. Firstly, the upper and the lower contact pins each has a complex structure, and are not easy to be manufactured. Secondly, the contact terminal has an unstable contacting between the upper and the lower contact pins because contacting surfaces between the upper and the lower contact pins are the inclined guiding surfaces of the hooks which are rough and the surfaces of the openings which are rough, so as to effect electrical connection of an electrical connector.
Hence, it is desirable to provide an improved contact terminal to overcome the aforementioned disadvantages.